This program is a study of the cellular basis of taste. The approach is biochemical and focuses on cellular recognition of sapid compounds. Methods of studying taste are based on measuring the direct attachment (binding) of C14-labeled taste stimuli to preparations from taste papillae. It is proposed to develop additional assay methods using "site-specific probes" for taste receptor molecules. These assays will be used to aid in the isolation of taste receptor molecules and in the study of their mechanisms of action.